This invention, which was made under a contract with the United States Department of Energy, relates to an improved method and apparatus for separating materials having different magnetic properties.
Impurities such as iron pyrite have previously been separated from pulverized coal by magnetic devices. However, many of the known types of magnetic separators use magnetized collectors from which a separated constituent of a coal mixture must be periodically removed. Although efforts have also been made to use a magnetic field to deflect magnetic material traveling along a path and thereby separate it from non-magnetic material associated therewith, known devices utilizing this principle of operation have not been practical for use in large scale commercial operations because of their inabilities to generate the required magnetic field in a large volume.